Method of mounting coiled filaments



Oct; 29, 1929; J J HIGG|NS 1,733,802

METHOD OF MOUNTING COI LED FILAMENTS Filed May 12, 1924 I IN TOR JOHNJ. q uvs 7 BY bl/ ATTORNEY Patented Oct. 29, 1929' UNITED STATES PATENT orrics JOHN JOSEPH HIGGINS, OF EAST ORANGE, NEW JERSEY, ASSIGNOit '10 WESTINGHOUSE LAMP COMPANY, A CORPORATION OF PENNSYLVANIA mnrnon or MOUNTING COILED FILAMENTS' Application 51nd a 12,

This invention relates to the art of manufacturing incandescent electric lamps and more particularly to the method of mounting lamp filaments.

An object of the invention is to expedite the mounting of lamp filaments during the manufacture of incandescent electric lamps, I

A further object is to facilitate the handling and application of a filament to the supporting structure of'an incandescent electric lamp. Y

A still further object of the invention is to avoid certain laborious and time consuming steps heretofore prevalent when performing mounting operations.

Other objects of the invention will be more readily apparent as the description proceeds.

One of the important and diificult operations included in the manufacture of incandescent electric lamps, is the application of the filament or light source medium to the lamp-stem, to constitute the internal structure of a lamp. The present invention has to do with the rapid automatic mounting of such filaments and particularly with the mounting of coiled filaments; namely, filament wire wound in the form of a helix, which filament 'is employed in lampsof the concentrated light source type. In this type, the main portion of the filament is supported by a number of loops at the ends of support wires secured in a glass portion of the stem.

The ends of the filament are usually welded to the ends of suitably positioned leading-in wires. It has been the practice, when mounting a filament of this character, to provide the coiled filament, in'sections ofthe proper length whereupon the operator first secures by weld ing, one end of the coil to a lead-in wire. The operator then threads the filament. into loops previously formed at the exposed ends of the support wires and then-holds the other end of the filament in contact with, remaining lead-in wire and Welds it thereto.

It will be appreciated that the foregoin operation is not only tedious, but requires considerable dexterity on the part of the operator in order that the required amount of filaments be mounted in a given time. This mounting operation must be performed by a 192 .1.v Serial No. 712,577.

slrilled operator to be maintained on a production basis in accordance with standards set by other machines or operators. The manual method of mounting, required that the operator picknp the extremely small flexible filaments with a pair of tweezers and this operation itself is indicative of the amount of labor and the degree of skill required to expeditiously perform this operation.

The present invention aims to provide a method by which the filament may be handled without the tedious operation which attends ing of the filament for a mounting operation I by providing the filament with a flexible core as for example by winding the filament on a thread or metallic strand of low fusing point. The filament wound on a mandrel of the above character, may then be readily handled and fed through a'guide and to posltion with, respect to a properly disposed lamp stem. A section of the filament sufficient to constitute a light source, may then be severed and shaped to circular form and applied to loops at the ends of support wires of a lamp stem. The lead-in wires of the stem being so arranged that they will be disposed in contact with electrodes of welding jaws after which companion jaws may travel to press the end of the filament against the lead and complete an electrical circuit, thus securing the filament to the lead wire. The lamp stem may then be removed and by reason of the elasticity of the support wires and the union of the filament to the leads, the filament will be supported-upon the stem.

It will be understood that by reason of the mandrel or core within the filament, the filabeen secured to the lamp stem. A removal of the mandrel may, in the event that such mandrel is in the form of a thread, be efi'ected by placingthe filament in a hydrogen furnace or byflashing the filament in a suitable inert atmosphere. WVhen a metallic mandrel of low fusing point is employed, the same may be removed .by subjecting the, filament; to a suflicient hightemperature which will cause- 'the core to melt out, which temperature may n:ot,however-, be sufliciently high to affect the filament prior to the application thereof to the supports of a lamp stem;

Fig. 4 shows elements formaintaining the filament adjacent the support wires;

Fig. 5 indicates welding jaws for securing the filament to the lead-in wires; Fig. 6 is a sectional view of a block which serves to maintain the support wires in given positions; I

Fig. 7 is a view of the block shown in Fig. 6 and shows other elements for holding a filament'in contact therewith; and, ,Fig. 8 is afragmentary view of a lamp stem showing a filament carried on the. supportwires thereof.

When'practicing the present invention, I may employ a spool 10 of'any suitable filament wire 11. The filament 11 may be led over a roller 12ofany suitablewinding head 13. The winding head maybe similar to those well knownin' the art and adapted to wind the filamentaboutamandrel 14. The mandrel may comprisea thread or may be a flexible or malleable metallic material of a'relati'vely low fusing point. The mandrel be initially wound on a spool 15 and may passt'hrou'gh the winding head 13 and around a"drum"16"ja'n'd thence to an idler 17 and t hrjough asuitabletub'ular guide 18.

' Suitable mechanism may be providedto reci roca e thegiiide 18 along the wire wound mandrel. jaws of any desirable c'on' structionirnity be associated with'the guide 1 8 ,ia's, for example, in the position as indiecat'ed by the-numeral 1 9. The jaws may op.- er'ateto engage with the coiled wire and mandrel andthr istth'emin'a rectilinear pa h a given distance withea'ch movement of the guide away from'fthefid'lr 17 given-portion-of'the mandrel ha'ving .the filament wound 'thereonjwilljfth-fusbe advanced with each of "said movements of; theguide: When the" guideis operatedito' move'asection of the wound mandrel, the section passes through an eyelet 21 in a plate which in conjunction with a jaw 22, may constitute a cut- The section of the wire thrust through the eyelet, is indicated by the reference numeral 23 and will hereinafter be termed the filament, which when severed from the main length'of wound mandrel, is ready for application to. a lamp stem 29, suitably sup ported in a holder 31. When the stem is in position to receive a filament, support wires 25 of the stem will be in position with respect j to a block 24 andlead-in wires 32 and 33 of the stem will be arranged with their ends adjacent to electrodes 34 in the block which cooperate with jaws 35, suitably positioned adjacent the block.

The jaws 35 may be arranged to move into contact and press the positioned filament ends against the lead-in wire at the same time closing a circuit to fuse the lead-in wire to the filament. The filament maybe brought to .position'for the fusing operation by any suitable means such as rollers 36 and 37 which are indicated as secured to shafts 38 and. 39,

'in position to be welded to the lead'in. wires "32 and 33. The welding jaws 35 maythen be moved to bring the filament in contact with the lead-in wires for the welding operation. The rollers 36 and 37 may be moved away from the filament and the'stem removed carrying'the filament which is resiliently retained' by reason of the looped portions of the supportwire and by the union of the leads to the filament. v

, After the filament or'filament wound mandrel has been mounted,it is, of course,'de-

sirable to remove 'the mandrel. This may be accomplished in'various ways. 'It has been foundthat a preferable 'method' is to place the filament in a hydrogen furnace, thereby heating the mandrel sufficiently to burn or melt the same from withiri the ,coil thus 1ea ing;the;usaa1"- helical 'filament'for the perature.

When ret1u1red, the ends of the support I wires 25-may'be bentaround the filament by .m'eansofanysuit'able tool, such as the member 3. were i -flewes may, however, be used to bend the supports about the filament to more positively secure the same to the stem.

, The presentinvention accomplishes an important step in the manufacture of incandescent electric lamps. It will be appreci-' ated that by reason of the manner of mounting the filament, the rate of production is greatly increased. By reason of the mandrel within the filament, sufiicient tensile strength is obtained to permit the feeding of the filament through the various operations necessary to automatic mounting without putting ment which comprises winding the filament on a mandrel, securing the filament to a lamp stem and removing the mandrel. I

2. The method of mounting a lamp fila-' ment which comprises winding the filament on a flexible mandrel, attaehing'the filament to a lamp stem and removing the mandrel.

3. The method of mounting a lamp filament which comprises winding the filament on a mandrel of relatively low fusing point, securing the filament to a lamp stem and removing the mandrel.

'4. The method of mounting a lamp filament which comprises winding a filament on a mandrel of low fusing point, securing the filament to a lamp stem and heating the filament toremove the mandrel therefrom.

5.- The method of mounting a lamp filament which comprises winding a filament on a core of low fusing point. securing the filament to a lamp stem and heating the filament in an inert atmosphere to melt the core therefrom.

6. The method of mounting a lamp filament which comprises winding a filament'on a, mandrel of low fusing point. securing the filament to a lamp stem and disposing the filament in a furnace to melt the mandrel therefrom.

7. The method of mounting a lamp filament wound on a mandrel of low fusing point, which comprises securing the filament to a lamp stem and heating the filament to melt out the mandrel.

8. The method of mounting a lamp fila-.

ment wound ona flexible fusible mandrel comprising attachingthe filament to a lamp stem and heating said filament in an inert environment to a temperature sufiicient to melt 'said mandrel from the filament.

9. The method of mounting a lamp filament'which comprises supporting a lamp stem having leading-in wires and support wires projecting therefrom, feeding a section of filament wire in the direction of its longitudinal axis to position adjacent to the ends of said support wires, bending the ends of the support wires around the filament and in securing the ends of said section of filament to said leading-in wires.

10. The method of mounting a lamp filament wound on a flexible mandrel which comprises supporting a lamp stem having loops in the support-wires thereof, positioning a section of the filament wound mandrel in said loops and securing the ends of said filament while on said mandrel to lead-in wires of said stem, and removing said mandrel from the filament.

11. The method of mounting a lamp filaity to said stem, severing a section of the filament, moving and shaping the severed section to position adjacent to the ends of said support wires, bending the said ends about the filament and securing the ends of the section of-filament to the leading-in wires of the stem.

12. The method of mounting a lamp filament wound on a flexible mandrel of relatively low fusing point which comprises moving a length of filament wound mandrel through a given path, to position a section thereof in close proximity to a lamp stem having loops in the support wires thereof, severing a section from the filament wound mandrel, shaping and moving said section to occupy said loops, securing the ends of the severed filament to the ends of lead-in wires of said stem, and heating said mandrel to remove the same from the filament.

13. A step in the method of mounting a lamp filament which comprises supporting a stem having leading-in wires and support wires incorporated therewith, moving'a filament of indefinite length in the direction of ment wound mandrel through a' given path,

to position; a section thereof in close prcx ends'of the severed filament to the ends oflead-in wiresof said stem.

15. The method of mounting a lamp filament which comprises winding a filament Wire on a mandrel of a relatively low fusing point, moving a length of filament Wound mandrel through a given path, to position a supports about the filament and removing section thereof in close proximitytoa lamp stem having loops in the support wires thereof, severing a section from the filament wound mandrel, shaping and moving said section to occupy said loops, securing the ends of the filament portion of said section to the ends of lead-in wires of said stem and heating said mandrel to remove the same from the filament.'

16. The method of mounting a lamp filament which comprises winding a filament wire on a mandrel of relatively low fusing point, moving a length of filament wound mandrel through a given path, to position a. section thereof in close proximity to a lamp stem having loops in the support wires thereof, severing a section from the filament wound mandrel, shaping and moving said section to occupy said loops, securing the'ends of the filament portion of said section to the ends of lead-in wires of said stem and removing the mandrel from the filament.

17 The method of mounting alamp filament which comprises winding a. filament wire on a mandrel of relatively low fusing point, moving a length of filament wound mandrel through a given path, to position a section thereof in close proximity to a lamp stem having loops in the support wires there-' of, severing a section from the filament wound mandrel, shaping and moving said section to occupy said'l.oops,securing the ends of the severed filament to the ends of lead-in wires of said stem and bending the ends of said t e mandrel from thefilament.

18. A'step in the method of manufacturing an incanclescerit'electric lamp which com prises supporting a lamp stem havin'g leading-m wires and supportwiresincorporated therewith, winding a filament wire to'".pro-'.

said bent,

ends bent to receive a filament, Winding a continuous length of filament wire to roduce a coiled filament, moving the coiled lament 'a predetermined distance to position a section thereof adjacent to the bent ends of said supports, severing a given length of said filament section and securing the ends of said section to said leading-in wires.

20. A step in the method of manufacturing an incandescent electric lamp which comprises supporting a lamp stem having leading-in wires and support Wires with their ends bent to receive a filament, winding a filament wire to produce a coiled filament, feeding the coiled filament to position a given length of filament thereof adjacent to the bent ends of said supports, severing said length, securing the ends of said length to said leading-in'wires and securing the leading-in wires to the ends of said length of filament.

21. Apparatusfor mounting a lamp filament upon a lamp stem having support wires andleading-in conductors which comprises feeding mechanism which moves a given length of filament from a supply of filament wire into a position in proximity to the ends of the support wires, mechanism which moves said length of filament into engagement with the ends of said support wires and mechanism for securing the ends of the filament to leading-in conductors upon said lamp stem.

22. Apparatus for mounting a lamp filament upon a lamp stem having support wires and leading-in conductors which comprises feeding mechanism which moves a given length of filament from a supply of filament wire into a position in proximity to the ends of the support wires, mechanism which moves said length of filament into engagement with the ends of said support wires and means for In testimony whereof, I have hereunto subname this 10th day of Mam-1924.

scribed my OHN JOSEPH HIGGINS.

duce a helix, moving the helically wound wire a given distance so a's:t'o position a section thereof of a predetermined length adjacent to the ends of" said support wires, severing said section, bending the'ends'ofthe support wires. around the" section and securing the ends of said section to saidleading-in wires.

"19. 'A step in the method of manufacturing an incandescent electric "lamp which comprises support-ing'a lamp stem having leadingdn wires and supportwires withtheir 

